Importance of water source in controlling leaf leaching losses in a dwarf red mangrove (Rhizophora mangle L.) wetland

Stephen E. Davis, Daniel L. Childers

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

The southern Everglades mangrove ecotone is characterized by extensive dwarf Rhizophora mangle L. shrub forests with a seasonally variable water source (Everglades - NE Florida Bay) and residence times ranging from short to long. We conducted a leaf leaching experiment to understand the influence that water source and its corresponding water quality have on (1) the early decay of R. mangle leaves and (2) the early exchange of total organic carbon (TOC) and total phosphorus (TP) between leaves and the water column. Newly senesced leaves collected from lower Taylor River (FL) were incubated in bottles containing water from one of three sources (Everglades, ambient mangrove, and Florida Bay) that spanned a range of salinity from 0 to 32‰, [TOC] from 710 to 1400 μM, and [TP] from 0.17 to 0.33 μM. We poisoned half the bottles in order to quantify abiotic processes (i.e., leaching) and assumed that non-poisoned bottles represented both biotic (i.e., microbial) and abiotic processes. We sacrificed bottles after 1,2, 5, 10, and 21 days of incubation and quantified changes in leaf mass and changes in water column [TOC] and [TP]. We saw 10-20% loss of leaf mass after 24 h-independent of water treatment-that leveled off by Day 21. After 3 weeks, non-poisoned leaves lost more mass than poisoned leaves, and there was only an effect of salinity on mass loss in poisoned incubations-with greatest leaching-associated losses in Everglades freshwater. Normalized concentrations of TOC in the water column increased by more than two orders of magnitude after 21 days with no effect of salinity and no difference between poisoned and non-poisoned treatments. However, normalized [TP] was lower in non-poisoned incubations as a result of immobilization by epiphytic microbes. This immobilization was greatest in Everglades freshwater and reflects the high P demand in this ecosystem. Immobilization of leached P in mangrove water and Florida Bay water was delayed by several days and may indicate an initial microbial limitation by labile C during the dry season.

Original languageEnglish (US)
Pages (from-to)194-201
Number of pages8
JournalEstuarine, Coastal and Shelf Science
Volume71
Issue number1-2
DOIs
StatePublished - Jan 2007

Keywords

  • Everglades
  • hydraulic residence time
  • limiting factor
  • organic carbon
  • phosphorus
  • salinity

ASJC Scopus subject areas

  • Oceanography
  • Aquatic Science

Fingerprint Dive into the research topics of 'Importance of water source in controlling leaf leaching losses in a dwarf red mangrove (Rhizophora mangle L.) wetland'. Together they form a unique fingerprint.

  • Cite this